Process and apparatus for continuous heat treatment of porous heavy webs

ABSTRACT

A process for the continuous heat treatment of heavy porus webs including rugs, carpets, heavy fiber fleeces, furniture coverings and the like, having a nap which comprises guiding said webs after having undergone a pretreatment, such as dyeing, to heat transfer zones of high effectiveness by passing a gaseous medium, for instance air, through said webs under pressure in a sense opposite to the weight pressure of the webs, or in some cases, from the underside of the web and additionally from above. The invention also relates to an apparatus for carrying out the process of the invention.

United States Patent 1 Meier-Windhorst 1 PROCESS AND APPARATUS FOR CONTINUOUS HEAT TREATMENT OF POROUS HEAVY WEBS [75] Inventor: Christian August Meier-Windhorst,

Hamburg, Germany [73] Assignee: Artos Dr. Ing. Meier-Windhorst,

Kommanditgesellschaft, Hamburg, Germany [22] Filed: Mar. 16, 1970 [21] App1.No.: 19,610

[30] Foreign Application Priority Data Mar. 19,1969 Germany ..P 1913 932.3

[52] US. Cl. 34/23, 34/115, 34/151,

[51] Int. Cl. F261: 3/00 [58] Field of Search 34/10, 23, 24, 115,

[56] References Cited UNITED STATES PATENTS 6/1937 Buck 34/158 X 7/1959 Thygeson 26/60 X June 19, 1973 1,383,510 7/1921 Bailey 34/115 920,351 5/1909 Layland et a1 34/115 2,265,071 12/1941 Hartenbach 1. 34/23 3,279,091 10/1966 Freuler 34/156 2,054,391 9/1936 Schmidt 34/115 2,728,129 12/1955 Koffman et a1.... 34/163 2,759,273 8/1956 Boyes 34/151 2,689,196 9/1954 Daniels 34/156 2,848,820 8/1958 Wallin et a1. 34/23 3,216,129 11/1965 Jepson 34/23 X Primary Exarr iiner Carroll B. Dority, Jr. Attorney-Allison C. Collard [57] ABSTRACT 5 Claims, 6 Drawing Figures Hal- Pmzmwwm 3.739.483

SHEEI 1 BF 2 INVENTOR CHRISTIAN AUGUST MEIER-WINDHORST By MQ mu;

Attorney 1 PROCESS AND APPARATUS FOR CONTINUOUS HEAT TREATMENT OF POROUS HEAVY WEBS The present invention relates to an apparatus and a process for the continuous heat treatment, more particularly the drying of porous heavy webs of goods, such as rugs and carpets, fiber fleeces, material for covering furniture and the like.

For the heat treatment, especially the drying of fabrics having a nap such as rugs, it is known to pass the webs on plate-like conveyers through the treatment chamber. In that case, the rugs are placed on the plates with the nap facing outward and the treatment agent is blown from above onto the rug, passes through the rug, and is sucked off through apertures in the conveyer plates. The rug dryers of this type are very expensive, because they have to be provided with conveyer plates of great width to accommodate the wide rug materials. in the treatment of the fabric webs, these dryers also have the drawback that the nap becomes compressed due to the placement of the webs on the nap.

Similar shortcomings are exhibited by other known rug dryers, in which the drying is done by aspiration drum dryers. Since the rugs are lying with their underside on the aspiration drums, in this case, too, the nap is compressed during treatment.

Accordingly, the present invention provides a process and apparatus which overcomes the abovementioned drawbacks of conventional processes and devices in preventing the nap of a rug and the like from being compressed during heat treatment due to the web being placed on a plate-like support. The webs of goods, after a pre-treatment, such as a dyeing operation are subjected to heat treatment zones of high heat transfer, in which a gaseous treatment medium is passed through the webs in an opposite sense to the weight pressure of the webs.

In carrying out this process, the webs may run on planar guide means and they are preferably aerated from the underside. The treatment medium will in that case, only pass upwards from below. It has found to be advantageous to provide ventilation for the aerating of the webs, preferably by the use of nozzles. In order to generate superpressure on the underside of the webs, all normally functioning escape openings should first be carefully sealed. in addition, an adjustable throttling means is provided for preventing escape of the treatment medium.

In another preferred embodiment of the invention, there may also be provided, in addition to the passage of ventilating means from below, ventilation from above, by means of area treatment carried out by nozzles.

When the webs of goods are conveyed over curved planes, it is advisable to have them passed from one heat treatment zone to the next on suspended, preferably adjustable loops, arranged in front of, and behind the heat treatment zones for increasing the pressure of the webs on the treatment zones, and thereby enhancing the flow of the treatment medium through the webs. As mentioned before, superpressure can be obtained above the web under treatment by proper guidance of the flow of the gaseous treatment medium near the two heat treatment zones; this results in an increase of the load, or pressure, of the web on the heat treatment zones and thereby an increased through-flow of the treatment medium through the web, at the same time increasing the heat transfer efficiency onto the web.

The superpressure can be obtained by appropriate resistance met by the air returned to the ventilators. By this means, the rug is somewhat blown up in the opposite direction, its flawless deflection is enhanced, and a slight repeat through-flow with repeated heat transfer increase is obtained.

To obtain an equilibrium between the action of pres sure by the through-flow of the treatment medium in the opposite sense to the load on the web, and the pressure or weight exerted by the web, and if needed, for additional superpressure loads between heat treatment zones, the rate of flow of treatment medium in said zones may be regulated.

It has also been found to be advantageous to provide additional guide means or holding means for the web at the edges, in cases where there are particular diffculties involved.

In the interval between two neighboring heat treatment zones, the webs under treatment may also be guided by drums or rollers. These drums or rollers may also be used as a means for passing the web through the treatment process.

A device for carrying out the process of the invention may e.g. consist of a clamping frame for continuous webs of goods, such frame having a known construc tion. The space below the tensioning chains forming part of such a device, forms a closed pressure chamber, and top closure being formed by the web itself. The device comprises connections for admission, and if desired, discharge of the treatment agent. For the regula tion of the superpressure, the device may be provided with throttle flaps built into the discharge means for the treatment medium. To obtain high treatment efficiency, the device may be provided with nozzles arranged in the pressure chamber, which provide area ventilation of the web from below, and additional nozzles for admission of treatment medium from above.

Another embodiment of the device according to the invention may consist of a closed casing, having entrance and exit slots, and in the casing, heat transfer elements with curved guide means for the web. The guide means are surrounded by jackets which have openings for the passage therethrough of a gaseous treatment medium from the interior of the heat transfer elements to the web in the direction opposed to the load on the web. The heat transfer elements may be stationary cylinders with apertures in their upper portion for the passage of gaseous medium therethrough, or they may be. rotating sieve drums with baflle plates screening off part of the drum space. Between two neighboring heat transfer elements, guide and/or conveyer means are arranged which are preferably permeable, and may be in the form of rotating cylinders or reels. In order to keep the pressure against the web low, the guide or conveyer means may have a larger diameter than the heat transfer elements.

In special cases, means may be provided for guiding the edges of the traveling web, said means consisting of tensioning chains for holding the web and guiding it along the entire width.

It is therefore an object according to the present invention to provide a process and apparatus which prevents the nap of a web of material from becoming compressed during its heat treatment on a plate-like support.

It is another object according to the present invention to provide a process and apparatus which overcomes the above-described disadvantages of conventional processes and devices.

It is still a further object of the present invention to provide a process and apparatus for the continuous heat treatment of material webs which is simple in design, and reliable in operation.

Other objects and features according to the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings which disclose the embodiments of the invention. It is to be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 shows an embodiment of the apparatus according to the invention for planar travel of the web to be treated, with the treatment medium being admitted from below only;

FIG. 2 illustrates an embodiment of the apparatus with air admission by nozzles from below and above;

FIG. 3 shows a heat treatment chamber with stationary heat transfer devices and deflecting return rollers at the bottom;

FIG. 4 is a similar chamber with freely suspended web loops between the heat transfer devices;

FIG. 5 shows rotating sieve drums as heat transfer devices, and

PEG. 6 illustrates a particular embodiment of the defleeting rollers at the bottom.

Referring now to FIGS. 1 and 2, for essentially planar travel of the web, FIG. 1 shows an apparatus generally designated by A and comprising a pressure chamber 19, an inlet port 20 for the admission of the treatment medium and mounting means 13 for circular tensioning chains 18 which hold web which forms the upper closure member of the chamber. Chains 18 may be conventional, endless tenterhook chains, having the hooks thereof disposed through the edges of the web, disposed in guide tracks for guiding the chains, and mounting means 13 may be a conventional tension frame for mounting the endless chains on pressure chamber 19 and for tensioning the webs of material. Web 10 is shown in a curved line which indicates that it is lifted in its middle portion by the superpressure generated by the treatment medium entering through inlet 20 and acting as indicated by the arrows, from below only.

In FIG. 2, the web is indicated at 110, the pressure chamber at l 19, mounting means for tensioning chains 118, at element 113. For intensifying the treatment, nozzles 21 and 22 are shown with ports 23 and 24, respectively for admission of the treatment medium, which now acts from below and above on web 1 10. The nozzles may be in the form of slots, circular or flat shape.

FIG. 2 further shows a pipe 25 for the escape of treatment medium, inasmuch as it has not been used by passing through the web or has not left the apparatus at conventional outlets. In pipe 25, a throttling valve 26 serves for accurate adjustment of the superpressure obtaining in pressure chamber 119. Experience has shown that with an accurately adjusted superpressure below the web by a strong throttling of the escaping air, ventilation from below is possible which leads to only 2 to 4 mm superpressure WS and results in an increase of drying performance about 50 to percent above that of known rug dryers.

FIGS. 3 and 4 show dryers wherein the web is traveling in an enclosed casing over rollers.

Referring more particularly to FIG. 3, the apparatus includes the casing 211, web 210, and an inlet opening 214 for the web, and an outlet opening 215. The rollers 213 which serve as heat transfer means, consist of stationary cylinders having in their upper walls openings 212 for passage of the treatment medium. In its travel from one roller 213 to the next one, the web is guided over return or deflecting rollers 216.

In. FIG. 4, the closed casing is designated by 31 1, and the heat transfer cylinders by 313, the arrangement being generally similar. The difference in the arrangement is that web 310 is not guided between neighboring rollers 313, but is freely hanging in loops 317, whereby the area on which there is action of the treatment medium on the web is considerably increased.

In the embodiment shown in FIG. 5, instead of stationary cylinders 213, rotating sieve cylinders 413, are provided, over which web 410 is made to travel. In that case, it is necessary to provide baffle plates 415 for that part of the cylinders where the web does not travel near their circumference in order to prevent the treatment medium from free escape. A reel 417 is shown in this embodiment for the return of the web to the next cylinder 413.

Finally, FIG. 6 shows an embodiment of the device similar to the one shown in FIG. 3. The web is 510, the heat transfer rollers are 513 with openings 512. In this case, however, the bottom return roller 516 is provided with a larger diameter. This has the advantage that the pressure where the web lies against the roller with the nap, is not excessive even when large amounts of treatment medium are blown through the web at the heat transfer devices. With this embodiment of the device, there is the advantage that due to the large diameter of rollers 516, the web will travel near the surface of the heat transfer rollers for a longer path, as FIG. 6 shows, so that the effective treatment section will be larger than, for example, in the embodiment of FIG. 3.

While only a few embodiments of the present invention have been shown, it will be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the inventlon.

What is claimed is:

1. A process for continuously heat treating heavy, porous webs of material having a nap, including rugs, carpets, heavy fiber fleeces, furniture coverings and the like, which have undergone pretreatment processes, such as dying, comprising the steps of guiding the webs over at least one heat transfer zone of high effectiveness and forcing a gaseous medium supplied from below through the underside of said webs in a direction opposite their weight pressure thereby avoiding compression of the nap.

2. The process according to claim 1, wherein the gaseous medium is supplied through nozzles, a superpressure being generated at the underside of the webs by throttling the escape of the gaseous medium.

3. The process according to claim 1, wherein as an additional heat treatment of the web the gaseous mev ing a continuous web, means for holding said web under tension, a pressure chamber below said web, said web forming the closure member at the top of said pressure chamber, nozzles for admission and pipes for escape of a gaseous treatment medium, said pipes including throttling valves for generating a superpressure in the pressure chamber for increasing the intensity of the heat treatment, so that a force is exerted upwardly on the web by the gas impinging thereon from below thereby preventing compression of the nap during the heat treatment. 

2. The process according to claim 1, wherein the gaseous medium is supplied through nozzles, a superpressure being generated at the underside of the webs by throttling the escape of the gaseous medium.
 3. The process according to claim 1, wherein as an additional heat treatment of the web the gaseous medium is also supplied thereto from above at a pressure lower than that exerted by the gas from below.
 4. The process according to claim 1, wherein said webs are passed over adjacent heat transfer zones with generation of superpressure therebetween, thereby increasing the effectiveness of the treatment of the gaseous medium on the webs.
 5. An apparatus for the continuous heat treatment of heavy, porous webs of material having a nap, including rugs, carpets, heavy fiber fleeces, furniture coverings and the like, said apparatus comprising means for guiding a continuous web, means for holding said web under tension, a pressure chamber below said web, said web forming the closure member at the top of said pressure chamber, nozzles for admission and pipes for escape of a gaseous treatment medium, said pipes including throttling valves for generating a super-pressure in the pressure chamber for increasing the intensity of the heat treatment, so that a force is exerted upwardly on the web by the gas impinging thereon from below thereby preventing compression of the nap during the heat treatment. 